Cap for electrical plug connections



Oct. 25, 1966 M. E. TRAGER CAP FOR ELECTRICAL PLUG CONNECTIONS Filed April 21, 1964 mm W W United States Patent 3,281,755 CAP FOR ELECTRICAL PLUG CONNECTIONS Martin E. Trager, Rte. 4, Box 236, Traverse City, Mich. Filed Apr. 21, 1964, Ser. No. 361,340 3 Claims. (Cl. 339--89) This invention relates to the general field of electric extension cords and other types of electrical wires or cables wherein a pronged type plug or male connector and a socket type plug or female connector is employed for deta-chably connecting together a pair of such wires or cables and, more specifically, the instant invention pertains to means for preventing the inadvertent or aocidential separation of the connector means.

One of the primary objects of this invention is to provide a cap for preventing the inadvertent or accidental separation of female and male connector plugs, the cap being readily removable to permit deliberate separation of the plugs and wherein the cap may be easily installed around the plugs without resort, in either case, to the use of mechanics tools.

Another object of this invention is to provide a cap of the type to which reference has been generally made above which will accommodate extension cord or cable connectors of varying sizes.

This invention contemplates, as a still further object thereof, the provision of a cap of the type described above, the cap being non-complex in construction and assembly, inexpensive to manufacture and maintain, and which is durable in use.

Other and further objects and advantages of the instant invention will become more evident from a consideration of the following specification when read in conjunction with the annexed drawing, in which:

FIGURE 1 is a side elevational view, partly broken away, of a cap constructed in accordance with this invention, FIGURE 1 showing the component elements of the cap in their respective positions just prior to the installation of the cap on a plug-type electrical connector;

FIGURE 2 is a medial longitudinal, cross-sectional view showing the operative positions of the several component elements of the cap when the cap is assembled over a plugtype electrical connector;

FIGURE 3 is a detail cross-sectional view, FIGURE 3 being taken substantially on the vertical plane of line 3-3 of FIGURE 2, looking in the direction of the arrows;

FIGURE 4 is a perspective view of the female element of the cap;

FIGURE 5 is a perspective view of the male element of the cap;

FIGURE 6 is a perspective view of one of the locking rings used in this construction; and

FIGURE 7 illustrates a side elevational view, partly broken away, of a second embodiment of this invention.

Before entering into a detailed explanation of the apparatus of the present invention, it will be understood that the invention is not limited in this application to the specific details of construction and the arrangement of parts illustrated in the accompanying drawing, since it is appreciated that the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it will be understood that the phraseology and terminology herein employed is for the sole purpose of description and is not to be construed as being of limitation.

Referring now more specifically to the drawing, reference numeral 10 designates, in general, a cap constructed in accordance with the teachings of this invention. The cap 10 is preferably formed of any desirable flexible, electrically non-conducting material and is seen to comprise a female element 12 which includes an elongated substantially hollow cylindrical main body portion 14- internally threaded as at 16. One end of the main body portion 14 terminates in a substantially hollow frustoconical end wall 18. As is seen in FIGURES 2 and 4-, the apex end of the end wall 18 terminates in a substantially hollow neck 20 externally threaded as at 22. The main body portion 14, the frusto-conical end wall 18, and the neck 22 are provided with a continuous axially-elongated slot 24.

Reference numeral 26 denotes, in general, a substantially hollow locking ring which comprises a substantially hollow cylindrical member 28 internally threaded .as at 30. The hollow cylindrical member 28 is provided, at one end thereof, with a frusto-conical end wall 32 having a bore 34 extending axially therethrough. As is seen in the drawing, the bore 34 has a lesser diameter than the internal diameter of the hollow cylindrical member 28, thereby providing an internal stop shoulder as, the function of which will be described below.

The male element of the cap 10 is generally designated by reference numeral 40, and the male element is seen to include a substantially hollow cylindrical main body portion 42 externally-threaded as at 44. One end of the main body portion 42 continuues into a substantially hollow frustoconical end wall 46, and the outer end of the latter extends into a substantially hollow cylindrical neck 48 externally-threaded, as at 50. The hollow cylindrical main body portion 42, the frusto-conical end wall 46, and the hollow cylindrical neck 48 are provided with a continuous axially-extending slot 52.

The above-described elements comprise the components of the cap 10 with the exception that while but one of the locking rings 26 has been described, two are actually employed. Since both locking rings are identical in construction, the description of one will serve as the description of the other which will be assigned the same reference numerals to which a prime mark has been added for the purposes of identification.

To utilize the cap 10, it is only necessary to thread one of the locking rings 26 on the neck 20 until the shoulder 36 engages against the outer end of the neck 20 after which the locking ring 26 is backed olf and rotated until the slot 38 formed therein is aligned with the slot 24.

The second locking ring 26' (see FIGURE 1) is now threaded on the neck 48 in the same manner, that is, until the shoulder 36 thereof engages against the outer end of the neck 48 at which time the locking ring 26 is backed off until the slot 38 is aligned with the slot 52. The cap 10 is now ready for connection about a pair of electric line or cable connectors.

Reference numeral 54 generally designates a conventional female connector plug connected in the usual manner to one end of an electrical first line or cable, and reference numeral 58 designates a male connector plug connected to one end of a second electricalc-onducting' line or cable tit In FIGURE 1 of the drawing, the male and female connector plugs 58, 54, respectively, are shown in their usual connected positions. Wit-h the female element 12, the cap 10 and its associated lock ring disposed in the manner described above, that is, with the slots each aligned with one another, and with the male element 40, the cap 10 and its associated lock ring 26 aligned with one another, the user of the cap 10 now positions the female connector plug 54 and the male connector plug 58 between the main body portions 14, 42 of the cap 10 (which have been placed in confronting relationship relative to one another) and thereafter passes the portions of the lines 56, 66) through the aligned aforementioned slots, thereby disposing the line portions in the female element 12 and the male element 40 of the cap 10. The lock rings 26, 26' are now rotated to close the slots 24 and 52, respectively, and the operator now draws upon the line 56 in such a manner as to cause the connected female and male connector plugs 54, 58,

respectively, to enter the female element 12 and to effect engagement of the female connector plug 54 with the frusto-conical end wall 18. Thereafter, the male element 40 of the cap is threaded into the female element 12 until the frusto-conical wall 46 engages against the adjacent end of the male connector plug 58. The female and male connector plugs 58 and 54, respectively, are now securely held against separation.

To remove the cap 10 from around the female and male connector plugs 54, 55 from around the female connector plug 54 and the male connector plug 58 it is only necessary that the above-stated assembly steps be carried out in reverse.

It should be here noted that the female element 12 and the male element 40 of the cap 10 are of identical construction with the exception of the diameters of the main body portions 14 and 42 and the fact that one is internally-threaded, while the other is externally-threaded.

FIGURE 7 of the drawing illustrates a second embodiment of this invention wherein only a male element 70 of the cap 10 has been illustrated. The male element 70 is seen to include an elongated substantially hollow, cylindrical main body portion 72 externally-threaded as at 74. Integral with one end of the main body portion 72 and extending thereacross is a substantially fiat end wall 76 which continues into an elongated substantially hollow cylindrical neck 78 externally-threaded as at an. The hollow cylindrical main body portion 72, the end wall 76 and the neck 78 are all provided with a continuous slot 82. Mounted on the neck 78 is a locking ring 26.

The male element 70 and its associated locking ring 26 function in the same manner as the male element 46 and its locking ring 26 and, in fact, could be substituted therefor if so desired. Again, a female element could be used with the male element 70, the female element corresponding exactly to the construction of the male element with the execption that in this case the internal main body portion of the female element would 'be internally-threaded instead of externally-threaded, as'shown at 74 in FIGURE 7.

Having described and illustrated two embodiments of this invention in detail, it will be understood that the same are offered merely by way of example, and that this invention is to be limited only by the scope of the appended claims.

What is claimed is:

1. A cap for enclosing an electrical connector having a pair of opposed ends with electric line means extending away from each end thereof, said cap including a female element having a substantially hollow cylindrical internally-threaded main body portion provided with a pair of opposed open ends, a first frusto-conical end wall projecting away from one of said ends of said female element, said main body portion and its said end wall having a continuous slot formed therein extending from end-to-end thereof, said main body portion 'being adapted to receive said connector with one of its said ends seating against said end wall with the adjacent line means extending through said end wall, mean mounted on said end wall operable to open and close said slot, an elongated male element comprising an externally-threaded substantially hollow cylindrical main body portion having a pair of opposed open ends, said main body portion of said male element having a substantially hollow frustoconical end wall projecting away from one of its said ends, said main body portion of said male element and its said end wall having a continuous slot therein extending from end-to-end thereof, said main body portion of said male element threadedly engaging with said main body portion of said female element with said end wall of said male element threadedly engaging within said main body nector and with its adjacent line means extending through said last-named end wall, and means on said last-named end wall operable to open and close said slot formed therein.

2. A cap for enclosing an electrical connector as defined in claim 1, wherein each of said end walls at the apex end thereof is provided with a longitudinally-extending substantially hollow cylindrical neck, each of said necks having an axial slot formed therein and communicating with, respectively, said slots formed in said male and female elements, each of said necks having the adjacent line means disposed therein, and wherein said means for opening and closing said slots are mounted, respectively, on said necks.

3. A cap for enclosing an electrical connector as defined in claim 2, wherein each of said necks is externallythreaded, and said last-named means comprises an internally-threaded lock ring threadedly engaged on said necks.

References Cited by the Examiner UNITED STATES PATENTS 1,536,738 5/1925 Wirkkala 24-123 2,565,605 8/1951 Grayson 24-114.5 2,707,273 4/1955 Klassen 33989 2,726,374 12/1955 Lipton 339- EDWARD C. ALLEN, Primary Examiner.

W. DONALD MILLER, Examiner. 

1. A CAP FOR ENCLOSING AN ELECTRICAL CONNECTOR HAVING A PAIR OF OPPOSED ENDS WITH ELECTRIC LINE MEANS EXTENDING AWAY FROM EACH END THEREOF, SAID CAP INCLUDING A FEMALE ELEMENT HAVING A SUBSTANTIALLY HOLLOW CYLINDRICAL INTERNALLY-THREADED MAIN BODY PORTION PROVIDED WITH A PAIR OF OPPOSED OPEN ENDS, A FIRST FUSTO-CONICAL END WALL PROJECTING AWAY FROM ONE OF SAID ENDS OF SAID FEMALE ELEMENT, SAID MAIN BODY PORTION AND ITS SAID END WALL HAVING A CONTINUOUS SLOT FORMED THEREIN EXTENDING FROM END-TO-END THEREOF, SAID MAIN BODY PORTION BEING ADAPTED TO RECEIVE SAID CONNECTOR WITH ONE OF ITS SAID ENDS SEATING AGAINST SAID END WALL WITH THE ADJACENT LINE MEANS EXTENDING THROUGH SAID END WALL, MEANS MOUNTED ON SAID END WALL OPERABLE TO OPEN AND CLOSE SAID SLOT, AN ELONGATED MALE ELEMENT COMPRISING AN EXTERNALLY-THREADED SUBSTANTIALLY HOLLOW CYLINDRICAL MAIN BODY PORTION HAVING A PAIR OPPOSED OPEN ENDS, SAID MAIN BODY PORTION OF SAID MALE ELEMENT HAVING A SUBSTANTIALLY HOLLOW FUSTOCONICAL END WALL PROJECTING AWAY FROM ONE OF ITS SAID ENDS, SAID MAIN BODY PORTION OF SAID MALE ELEMENT AND ITS SAID END WALL HAVING A CONTINUOUS SLOT THEREIN EXTENDING FROM END-TO-END THEREOF, SAID MAIN BODY PORTION OF SAID MALE ELEMENT THREADLY ENGAGING WITH SAID MAIN BODY PORTION OF SAID FEMALE ELEMENT WITH SAID END WALL OF SAID MALE ELEMENT THREADLY ENGAGING WITHIN SAID MAIN BODY NECTOR AND WITH ITS ADJACENT LINE MEANS EXTENDING THROUGH SAID LAST-NAMED END WALL, AND MEANS ON SAID LAST-NAMED END WALL OPERABLE TO OPEN AND CLOSE SAID SLOT FORMED THEREIN. 